This invention relates to flexographic printing rolls.
In order to print a repetitive pattern, such as on fabrics or wallpaper, it is known to form a printing roll using a steel base tube and bonding an elastomeric sleeve on the base tube. The sleeve can then be hand engraved or stereos can be mounted on it. This form of printing is known as "flexographic printing". A typical roll is 15 cms diameter and 2 meters long. (Flexographic printing can also be used for transfer paper printing, direct textile printing - simplex and Duplex - linoleum, floor covering and carpet printing, and for printing packaging materials).
Such a printing roll is cumbersome to handle, expensive to transport and store and costly to service when the engraved sleeves or mounted stereos wear.
The manufacture of inking and printing rolls by the application of an air expanded sleeve to a rigid base tube is known, but to my knowledge this technique of manufacture has not been applied to the manufacture of engraved flexograhic printing rolls. As flexographic printing is used for very accurate high quality overlay color printing where perfect conjugation and intensity of the overlaid colors is vital, and as flexographic printing frequently involves the use of massive rolls (typically 15 cms in diameter and 2 meters long), and the accuracy has to be sustained over the large surface area of the rolls, I consider that the teaching to be derived from known techniques is inadequate.